Effect of mechanical planting methods and seeding rates on yield, earliness and technological properties of some Egyptian cotton varieties.

摘要

The effect of mechanical sowing methods (40 x 80 and 60 x 60 cm between ridges) and seeding rates (15 and 25 kg/feddan) on yield and earliness of cotton cultivars (Giza 80 and Giza 83) were determined in a field experiment conducted in Egypt for 2 successive seasons (1996-97 and 1997-98). Technological properties were compared to the manual method. The results indicated insignificant effects of planting methods on earliness, whereas seeding rate at 25 kg/feddan enhanced earliness index in one season compared to 15 kg/feddan. Number of sympodia, boll weight, seed and lint indices were not affected by the sowing methods. Seeding rate at 15 kg/feddan increased boll weight and number of sympodia. Giza 83 recorded the highest seed cotton yield (13.17 kentar/feddan) with 40 x 80 cm followed by 60 x 60 cm mechanical sowing method (12.95 kentar/feddan) and manual sowing (12.08 kentar/feddan). Fibre length at 50 and 2.5% span length, uniformity percentage, fibre strength in gram/tex, elongation percentage, fibre maturity as measured by maturity ratio, maturity percentage, hair weight and Micronaire reading, and lea product were not affected by the planting methods and seeding rates. Mechanical sowing method at 40 x 80 cm was superior in most of the agronomic and technological properties. The percentage of total costs ranged from 19.82 to 22.78% for the mechanical methods, and from 24.64 to 29.23% for manual sowing in the first season; and from 22.82 to 24.82% for the mechanical methods and from 30.57 to31.97% for manual sowing in the second season.